Blender Trim Sheet UV's not unwrapping
There is nothing wrong with the UV map you created. Using Follow active quads gives you good uv islands suitable for trim maps.

You should instead focus on how you built the model. Try to keep your quads as square as possible so that the distortion gets evenly distributed across all faces.

I added a wireframe to the model so that you can see how the quads gets split up into triangles and how the texture stretches over them.